WINETECH Technical Yearbook 2019

undergone sur lie and the completion or initiation of malolactic fermentation (MLF). If a co-inoculant was not used, the latter can continue until after harvest, especially when the temperature starts to decrease. It can even in some cases continue until the next spring, before it is completed. Wines are in particular exposed to oxidation between alcoholic fermentation and the completion of malolactic fermentation. Sulphur dioxide adjustments can also not be made, before MLF is completed. It is consequently even desirable to heat wines to ensure that the desirable Oenococcus species complete MLF timeously. After the MLF completion, a high sulphur dioxide addition instead of a few low ones can be made. While waiting for the completion of MLF, the time can be utilised advantageously to have a post-mortem discussion on the finished vintage. All employees should be involved, before they leave for their deserved holidays. This discussion should not address the winemaking, but rather focus on the processes and equipment that were used. Seeing that it is too early to evaluate the success of the winemaking, aspects like staff scheduling, equipment needs and cellar capacity must rather be discussed. Resolutions must be noted to monitor their execution. The terms cleaning, sanitation, disinfection and sterilisation are often used as if they are the same action. It is however individually

The harvest is the climax of all winemakers’ lives. Late and some sleepless nights typify this time of the year. Grapes must be monitored, juice prepared for fermentation, yeast cultures prepared and the alcoholic fermentation must be monitored and managed. The birth of a young wine introduces another vintage which will be drunk some or other time. The rest of the year can however not be neglected to ensure that the results of the harvest are maintained and the necessary preparations for the next vintage are implemented timeously. The end of harvest is typified by the completion of certain cellar practices and the production of the young wine. It comprises amongst other the last pressing of red skins, the racking of white wines, which has CHARL THERON: Private consultant KEYWORDS: Cleaning, sanitation, maintenance. MAY 2019 POST-HARVEST PRACTICES IN WINE CELLARS

PHOTOS. Cleaning and sanitation of harvest equipment is essential.